The DC Appeals Court judge has an impressive resume and a long history of supporting right-wing positions like restricting abortion, opposing Obamacare and loosening environmental regulations.

But Kavanaugh has also argued that sitting presidents should be exempt from prosecution.

"Congress might consider a law exempting a President—while in office—from criminal prosecution and investigation, including from questioning by criminal prosecutors or defence counsel," Kavanaugh wrote in the Minnesota Law Review in 2009.

"Criminal investigations targeted at or revolving around a President are inevitably politicised by both their supporters and critics.

He also led an inquiry into the death of Vincent Foster, a White House aide whose 1993 suicide sparked countless conspiracy theories.

In his 2009 Minnesota Law Review article, Kavanaugh concluded it was a mistake to investigate Clinton.

"Looking back to the late 1990s, for example, the nation certainly would have been better off if President Clinton could have focused on Osama bin Laden without being distracted by the Paula Jones sexual harassment case and its criminal investigation offshoots," he wrote.

Kavanaugh added Clinton brought the "ordeal" on himself.

Brett Kavanaugh (second from left) was a powerful behind-the-scenes player in the Bush Administration. (AAP) (AAP)

"Brett Kavanaugh's record as a judge and lawyer is clear: hostile to health care for millions, opposed to the CFPB (Consumer Financial Protection Bureau) & corporate accountability, thinks Presidents like Trump are above the law – and conservatives are confident that he would overturn Roe v. Wade," she tweeted.